Ten Mile Raspberry Pi WiFi (with a Catch)
How would you like to have a WiFi connection that covers 10 miles? Or how about an even wider network made up of a mesh of multiple nodes? It is possible, but there is a catch: you probably need a ham radio license to do it (at least, you do in the United States).
What makes it possible is the realization that conventional WiFi channels 1-6 are inside an existing US ham band. That means (if you are a ham) you can elect to use FCC part 97 rules instead of part 15 that governs WiFi routers. That means you …read more
WiFi Alliance Introduces 802.11ah
For the last decade or so, wireless networking has been entirely about short range, high speed communications. The type of networking needed by an Internet of things is fundamentally incompatible with WiFi, and the reason for this is due to the frequencies used by WiFi networking gear. 2.4 and 5 GHz are very fast, but cannot penetrate through walls as easily as lower frequencies.
This week the WiFi alliance introduced IEEE 802.11ah into the WiFi spec. It’s called WiFi HaLow (pronounced like angel’s headwear), and unlike other versions of 802.11, WiFi HaLow uses low frequencies for low bandwidth but a …read more
Henry Smolinski and the Flying Pinto
Anyone who has ever been stuck in gridlock has probably daydreamed about pushing a button on the dashboard that turns their car into a plane. Imagine how much more relaxing a weekend getaway would be if you could take to the open sky instead hitting the congested highway. For as long as there have been aircraft and automobiles, man has tried to combine the two. The proper term for this marriage is ‘roadable aircraft’, and a successful one requires attention to the aerodynamics of flight as well as the rigors of motoring.
One promising attempt at a roadable aircraft came …read more
Paddy Neumann’s Bounce Per Ounce is Better Than NASA’s
[Paddy Neumann] is an Australian physicist and founder of Neumann Space, a space start-up with a record-breaking ion drive.
The team at Neumann Space built an ion engine that broke the previous specific impulse (bounce per ounce) record. NASA’s HIPEP thruster previously held this record with a specific impulse of ~9600 seconds (+/- 200 seconds). The Neumann Drive’s specific impulse as recorded by the University of Sydney was ~14,690 seconds (+/- 2,000 seconds). This all equates to better efficiency by the Neumann Drive, however its acceleration does not match that of the HIPEP.
The Neumann Drive has another unique advantage …read more
The Unreasonable Effectiveness of Adhesive Tape
No doubt many of you have spent a happy Christmas tearing away layers of wrapping paper to expose some new gadget. But did you stop to spare a thought for the “sticky-back plastic” holding your precious gift paper together?
There are a crazy number of adhesive tapes available, and in this article I’d like to discuss a few of the ones I’ve found useful in my lab, and their sometimes surprising applications. I’d be interested in your own favorite tapes and adhesives too, so please comment below!
But first, I’d like to start with the tapes that I don’t use. …read more
